1. Field of Invention
The present invention relates to the method of preparing a shoe sole. More particularly, the present invention relates to preparing a shoe sole by partially vulcanizing the uncured rubber with laser irradiation.
2. Description of Related Art
Shoe sole is the bottom part of a shoe. Generally, a shoe sole has three parts, the insole, the midsole and the outsole.
The insole is the interior bottom of a shoe sole, which is in direct contact with the sock liner so as to provide good wearing comfort and protection. Insoles are usually made of cellulosic paper board or synthetic non-woven insole board.
The midsole is the layer between the outsole and the insole. The midsole may be made of a variety of materials to give the shoe various characteristics of cushioning, support, and flexibility. However, some shoes may not have a midsole at all.
The outsole directly meets the ground, and it is usually made of rubber, such as natural rubber or synthetic rubbers, depending on the design need. For example, black rubber outsole is a natural rubber or synthetic rubber with carbon black added, and the combination of these two materials creates a durable outsole suitable for working shoes. Also, the outsole may comprise a single piece, or may be an assembly of separate pieces of different materials. In the shoe industry, the outsoles are often referred to as the “sole” of the shoe.
The conventional way of making the outsole is complicated, time-consuming and costly. In one example, the uncured rubber and the vulcanization agent and/or other fillers are uniformly mixed together first, and then the mixed rubber is completely vulcanized in the mold with a predetermined shape with or without a pattern. However, molds for various shoe sizes should be made in order to produce various shoe sole sizes in some conventional production methods. Making those molds is expensive and time-consuming, resulting in high production cost. In addition, the outsole shapes and patterns are vulcanized and fixed during the vulcanizing process in the mold. If a new design and size of the shoe sole is needed, some additional cut or scribe processes are needed in order to modify the outsole shapes or patterns, or otherwise new molds need to be produced to fit the particular designs and sizes. Finally, the outsole is laminated with the midsole (if any) and the insole to become a shoe sole, and the shoe sole is stitched, glued or fixed to the other panels of the shoe to form a shoe.
In view of the foregoing, there exists a need in the art for providing a time- and cost-effective way for manufacturing outsoles.